A standard prenup agreement is a written contract two people sign before marrying that sets the rules for how their property, debts, spousal support, and inheritance rights will be handled if the marriage ends in divorce or death. It replaces whatever default rules your state would otherwise apply. The core provisions look similar across the country because roughly 28 states and the District of Columbia follow some version of the Uniform Premarital Agreement Act or its 2012 successor, and the remaining states tend to recognize the same categories of terms.
What a Standard Prenup Covers
Four areas make up the heart of almost every prenup.
Property and Assets
The central move is drawing a clear line between separate property and marital property. Separate property is what each person owned before the wedding, plus personal inheritances and gifts received during the marriage. Marital property is what the couple acquires together after the ceremony. The agreement labels each major asset and says what happens to it if the marriage ends.
Appreciation is where the real work happens. If you enter the marriage owning a business worth $500,000 and it grows to $700,000 over ten years, that $200,000 of growth can be contested. Without a prenup, a court might award the non-owning spouse a share, particularly if they contributed to the business or set aside career plans. A prenup can assign that growth entirely to the original owner, or create a formula for sharing part of it.
Debts
A standard prenup identifies pre-existing debts and assigns them to the spouse who brought them in. Student loans are the most common example: the agreement can state that loans incurred before the wedding stay with the borrower, shielding the other spouse from collection and from having the debt pulled into property division.
The harder question is debt taken on during the marriage. A prenup can require each spouse to carry their own credit accounts, set rules for shared obligations like a mortgage, and specify whether student loans for post-wedding education count as joint or individual. Without these terms, your state’s defaults control, and in community property states that often means both spouses share liability for debts incurred during the marriage regardless of whose name is on the account.
Spousal Support
Alimony provisions range from detailed payment formulas to outright waivers. Some agreements set a monthly amount tied to the length of the marriage. Others use a formula, such as a fixed dollar figure per year of marriage or a percentage of the higher earner’s income. Remarriage and cohabitation are the most common termination triggers.
A full waiver of alimony is allowed under the uniform acts and most state laws, but with a significant catch. If enforcing the waiver would leave the lower-earning spouse eligible for public assistance at the time of divorce, courts following the UPAA or its successor can override the waiver and order enough support to eliminate that eligibility. If a full waiver is on the table, both sides should know this backstop exists.
Some couples add lifestyle clauses, such as financial penalties for infidelity. Enforceability varies sharply. States that only allow no-fault divorce tend to refuse enforcement because the clause penalizes marital behavior, which conflicts with the no-fault framework. States that still recognize fault-based grounds like adultery are more likely to uphold them.
Estate and Inheritance Rights
Prenups don’t just govern divorce. Under the uniform acts, a prenup can address the disposition of property at death, the making of wills or trusts, and ownership of life insurance death benefits.1Uniform Law Commission. Uniform Premarital and Marital Agreements Act
Most states give a surviving spouse an elective share, typically one-third of the deceased spouse’s estate, regardless of what the will says. A prenup can waive that right. This matters especially in second marriages where one or both spouses want to preserve assets for children from a prior relationship. When a prenup and a will conflict, the prenup generally wins, because courts treat it as a binding contract while a will is a unilateral document the deceased could have changed at any time.
What a Prenup Can’t Decide
Some provisions won’t be enforced even if both spouses agreed to them.
Child custody and child support are off the table. No prenup can predetermine custody arrangements or set a child support amount. Courts hold exclusive authority over these decisions because they have to turn on the child’s best interests at the time of the dispute, not projections made before the child was born. If a prenup includes these clauses, those specific terms get struck, though the rest of the agreement can survive.
Terms that violate public policy or criminal law also won’t hold. The uniform acts explicitly prohibit provisions that run afoul of public policy or any statute carrying a criminal penalty.1Uniform Law Commission. Uniform Premarital and Marital Agreements Act You can’t use a prenup to encourage divorce (such as a bonus triggered only by the marriage ending), require illegal conduct, or impose terms so one-sided a court’s conscience would be shocked. An agreement that leaves one spouse unable to meet basic living needs is the classic example of a term courts refuse to enforce.
What Makes a Prenup Enforceable
Four things determine whether a prenup will hold up: full financial disclosure, voluntary signing, independent legal counsel, and proper execution.
Full Financial Disclosure
This is the single most important factor. Under both the UPAA and its successor, an agreement can be thrown out if the challenging spouse was not provided a reasonably accurate description and good-faith estimate of the other spouse’s property, debts, and income.1Uniform Law Commission. Uniform Premarital and Marital Agreements Act Disclosure isn’t optional transparency. It’s a prerequisite for the contract to survive a challenge.
In practice, that means compiling documentation for every significant asset and liability: bank statements, retirement account balances, real estate appraisals, tax returns, and outstanding loan balances. Each item should carry a current value backed by paperwork. Business owners face a steeper burden, because a closely held business or professional practice generally needs a formal valuation, and an undervalued business disclosed in bad faith can unravel the entire agreement.
The uniform acts do allow a spouse to expressly waive the right to further disclosure in a separate signed document, but a waiver only works if the waiving spouse already had adequate knowledge of the other’s finances or a reasonable basis for obtaining it.1Uniform Law Commission. Uniform Premarital and Marital Agreements Act A waiver doesn’t substitute for actual honesty when one spouse is in the dark.
Voluntary Signing and Timing
Both spouses have to sign voluntarily. Presenting the agreement for the first time the night before the wedding is the textbook example of pressure that courts point to when invalidating prenups. Signing should happen well before the ceremony, with enough runway for both parties to review the terms, consult attorneys, and negotiate changes without the clock running. Some states have codified specific waiting periods. An agreement signed at the rehearsal dinner has a short life expectancy in court.
Independent Legal Counsel
Independent counsel is not strictly required in most states, but skipping it is one of the riskiest shortcuts in family law. The updated uniform act allows a court to invalidate the agreement if the challenging spouse lacked access to independent representation, unless the agreement itself included a plain-language explanation of the rights being waived. Having each spouse represented by their own attorney dramatically strengthens the agreement. If one spouse chooses to go without counsel, the other should insist on a signed acknowledgment that the opportunity was offered and declined.
Writing, Signatures, and Notarization
Under the uniform acts, the only absolute formalities are that the agreement be in writing and signed by both parties. No additional consideration is required beyond the marriage itself.1Uniform Law Commission. Uniform Premarital and Marital Agreements Act Several states add requirements on top. Notarization is the most common extra; roughly eight states require notarized signatures for a prenup to be enforceable. Elsewhere, notarization is still worth doing because it makes it harder for a spouse to later claim the signature was forged or never happened.
How a Prenup Gets Thrown Out
Challenges to prenups fall into three categories.
- Involuntary execution or duress. If one spouse was coerced through threats, manipulation, or overwhelming pressure, the agreement is unenforceable. Duress can be physical, emotional, or economic. The challenging spouse carries the burden of proof, and courts look at relationship dynamics, timing, and whether the person had a meaningful opportunity to refuse.
- Inadequate financial disclosure. If one spouse hid assets, understated values, or failed to disclose debts, the other didn’t have what they needed to make an informed decision. This is probably the most common invalidation ground in practice because it’s concrete and provable. A spouse who later uncovers a hidden brokerage account or an undisclosed business interest has a strong argument.
- Unconscionability. An agreement is unconscionable when its terms are so lopsided that no reasonable person in the disadvantaged spouse’s position would have agreed. Courts look at both the substance and the circumstances. An agreement leaving one spouse destitute while the other walks away with everything is the kind of result courts refuse to enforce, especially when the disadvantaged spouse had no attorney.
Under the original UPAA, unconscionability alone isn’t enough; the challenging spouse must also prove inadequate disclosure. The newer Uniform Premarital and Marital Agreements Act tightened the standard by letting a court refuse enforcement if the challenging spouse lacked access to independent legal representation and the agreement didn’t include a plain-language explanation of the rights being waived.1Uniform Law Commission. Uniform Premarital and Marital Agreements Act Either way, the practical takeaway is the same: a transparent, balanced process is the best insurance against a future challenge.
Changing or Ending It Later
A prenup isn’t necessarily permanent. Under the uniform acts, it can be amended or revoked after the wedding, but only through a written agreement signed by both spouses. No additional consideration is required for the modification to bind. One spouse can’t unilaterally change or cancel it, and modifications can’t happen once the couple has separated or started divorce proceedings.
Couples whose circumstances shift significantly during the marriage have two choices. They can amend the existing prenup with a written addendum, or they can sign a postnuptial agreement that replaces some or all of the original terms. The enforceability standards are similar, though some states scrutinize postnups more closely because the parties are already married and bargaining power may be uneven.
Some prenups include a sunset clause that causes the agreement to expire after a set period of marriage (often 10 or 20 years), at a financial milestone like paying off a major debt, or at a life event such as the birth of a child. Once the trigger hits, the state’s default property and support rules take over. Couples approaching a sunset date who still want protection should negotiate a new agreement before the old one lapses.
What a Standard Prenup Costs
Attorney fees for drafting and reviewing a prenuptial agreement generally range from $1,000 to $10,000, depending on the complexity of the couple’s finances, how much negotiation the terms require, and local rates. Simple agreements between two people with modest assets and no business interests land at the lower end. Couples with business valuations, multiple properties, or heavily negotiated support terms push toward the upper end. Because each spouse should have independent counsel, the total is effectively doubled since both attorneys charge separately. Additional costs may include real estate appraisals, business valuations, and financial advisor consultations needed to complete the required disclosures.